Apparatus for automated synthesis of peptides

Abstract

A system maintained under a constant reference pressure for the automated synthesis of peptides includes a reaction vessel that has a single port for both injection and withdrawal of the various fluids used in the peptide synthesis sequence, a plurality of reservoirs for holding the amino acids used in the synthesis of the peptide chains and a plurality of reservoirs for holding the solvents and reagents used to promote the synthesis of the peptide chains. The system also includes a volume displacement pump for removing a controlled volume of gas from the reaction vessel as the first part of each injection step to reduce the pressure within the vessel. This is followed by connection of a selected reservoir to the reaction vessel and flow from the reservoir to the vessel resulting from the pressure differential between the vessel and the reservoir. As soon as the pressure in the reaction vessel has returned to reference level, the transfer is complete. Because all parts of the system are maintained at the reference pressure, metered transfer of reagents and solvents from the reservoirs to the reaction vessel can be performed easily without using a high vacuum. Transfer is self-terminating, and is readily controlled. Furthermore, the system easily accommodates wide volume ranges, and lends itself readily to automation.

What is claimed as new and desired to be secured by Letters Patent of the United States is: 
     
       1. A system for the solid-phase synthesis of peptides by successive amino-acid additions to peptide chains anchored to a solid support matrix, the system comprising: A. a reaction vessel enclosing the solid support matrix and comprising (1) a single port for bidirectional flow therethrough into and out of the vessel, and   (2) a porous filter positioned in the vessel adjacent the single port for retaining the solid support matrix in the reaction vessel while allowing passage of fluids from the vessel;     B. a plurality of reservoirs, each containing a solvent or reagent, or an amino acid used for the synthesis of said peptide;   C. means for supplying a reference pressure to the vessel and the reservoirs and the rest of the system;   D. means for removing a predetermined continuously variable volume of gas from the vessel; and   E. means for displacing said removed volume of gas with a predetermined volume of a selected solvent, reagent or amino acid from one of said reservoirs in response to the difference in pressure between the reference pressure and the pressure in the vessel.   
     
     
       2. A system as described in claim 1 and further including a processor for automatically controlling the supplying means, the removing means and the displacing means. 
     
     
       3. A system as described in claim 1 and further including exhaust means for emptying the reaction vessel. 
     
     
       4. A system as described in claim 1 and further including means for monitoring the yield of each amino acid addition. 
     
     
       5. A system as described in claim 4 and further including means for repeating the previous amino acid addition before proceeding to the next successive addition when the yield monitoring means detects a yield that is below a predetermined level. 
     
     
       6. A system for the solid-phase synthesis of peptides by successive amino-acid additions to peptide chains anchored to a solid support matrix, the system comprising: A. a reaction vessel enclosing a solid support matrix and comprising: (1) a single port for bidirectional flow therethrough into and out of the vessel, and   (2) a porous filter positioned in the vessel adjacent the single port for retaining the solid support matrix while allowing passage of fluids from the vessel;     B. a plurality of reservoirs, each containing a solvent or regent, or an amino acid used for the synthesis of said peptide;   C. transfer lines connecting said reaction vessel to said reservoirs;   D. means for maintaining a reference pressure in the system;   E. means for removing a predetermined, continuously variable volume of gas from said reaction vessel comprising syringe means connectable to said reaction vessel; and   F. means for transferring a measured, variable volume of a liquid, proportional to said volume of gas, from a selected one of said reservoirs to the reaction vessel through the transfer lines, said transferring means comprising: (1) valve means operable between (a) a first state in which said reaction vessel is closed to said reservoirs and said reference pressure and said reaction vessel is connected to said syringe means, and   (b) a second state in which said reaction vessel is closed to said syringe means and said selected reservoir is connected to said reaction vessel,        whereby a transfer of liquid from said reservoir to said reaction vessel occurs by (1) operating the syringe means while the valve means is in its first state to remove the predetermined volume of gas from said reaction vessel, and subsequently,   (2) operating the valve means in its second state so that liquid from said reservoir is transferred to said reaction vessel until the pressure in the reaction vessel reaches the reference pressure.